The proposed research addresses the issue of how knowledge of grammar interacts with other sources of information in processing and understanding language. This issue is addressed by focusing on the problem of how referentially dependant words (e.g., pronouns and reflexives) are interpreted. In particular, the research proposed here will endeavor to clarify how grammatical knowledge regarding allowable coreference relations enters into the process of determining their understanding, and how other information regarding the syntactic properties of a sentence may be exploited. Because pronouns only convey information regarding the gender and number of their referents, these forms cannot be fully interpreted without determining which entity in the discourse the pronoun is coreferential with. A broad range of types of information drawn from the sentence content, the discourse context, and the audience's background knowledge come to play a role in the interpretation of pronouns. One type of interpretive strategy that will be investigated is based on the grammatical roles of referring expressions. A closely related issue is how the syntactic relation between pronouns and referring expressions in a sentence governs the interpretation of the pronouns. There are stringent constraints governing which phrases in the sentence containing a pronoun can be coreferential with the pronoun. Resolving how these constraints exert their influence on the interpretation process can help to deepen our understanding of how the core component of linguistic competence, knowledge of grammar, contributes to language understanding.